Partially applied. The releases script doesn't currently handle the
situation where there isn't at least one tree with the "stable" moniker
-- which is a bug, but the fix is non-trivial and will require testing.
So, for now, until 4.10 is released, I'm not marking 4.9 as "longterm"
on the landing page in order not to break things. I will work on
adjusting the logic so that we don't have to do this in the future.

When 4.10 is out, I'll properly mark 4.9 as longterm on the landing page
-- for now it's only indicated as such on the releases page.